The groundhog P39 thread is without doubt one of the very best threads on this forum in my opinion, the stubbornness shown by it's OP to listen and learn anything and his blind belief in the P39's supposed outstanding performance brought out the most experienced members on here with their corresponding wealth of knowledge, every argument for the P39 was countered with facts not opinion or hearsay sprinkled with lots of humor making it a data base of information.
Effectiveness of the P-38
- Thread starter tomo pauk
- Start date
It is not a constant, it is a complex mathematical function. Bungays "The most dangerous enemy" has a section, concerning the Battle of Britain discussing claims and the errors involved. the number of eyes looking at the battle and the length of the engagement drive up the claims In the BoB everyone was looking for a "bounce" because a mixed up fur ball type engagement was rarely decisive. When small numbers engaged each other overclaiming was approx 2 times actual losses. When the big wing was involved they were much higher because there were more "eyes" and much more confusion. This problem probably reached its height with mass US and by huge am bomber formations under attack for hours, when you look at actual footage of what gunners were doing it is no surprise that they got things wrong and by a huge margin.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Agreed. A lot of aeronautical concepts had to be explained in a way that even I understood it. I remember X XBe02Drvr explained the concept of tail heavy by using a paper airplane. If you put a paper clip on the nose, okay. If you put on the tail, not so much. It was as educational as it was frustrating and comical.
Let's not forget that our expert was always a gentleman. He posted courteously and respectfully, no matter how much abuse was heaped on him. I try to keep that in mind with my postings.
Hey, anyone heard from X XBe02Drvr ?
I don't remember the groundhog P-39 thread, but it sounds like staked himself to a position and tried to defend it to the death.
A few years ago, however, I found some paper on the P-39 from the Thirteenth Air Force. The earlier report bemoaned the fact that even minor damage to the P-39's belly could cause a rapid loss of coolant, and the aircraft would soon be lost too. (This was 1942 over Guadalcanal.) The second report was from 1944 - patiently hoping to get more P-38s, the Thirteenth asked to send back any remaining P-40s and - in the interim - bring in more P-39s. I had always thought their preferences would have been the opposite!
Edwards Park (editor at Smithsonian) always had good things to say about the P-39, especially his aircraft Nanette, who always developed technical problems forcing him to return to base before a really tough mission.
Cheers,
Dana
A few years ago, however, I found some paper on the P-39 from the Thirteenth Air Force. The earlier report bemoaned the fact that even minor damage to the P-39's belly could cause a rapid loss of coolant, and the aircraft would soon be lost too. (This was 1942 over Guadalcanal.) The second report was from 1944 - patiently hoping to get more P-38s, the Thirteenth asked to send back any remaining P-40s and - in the interim - bring in more P-39s. I had always thought their preferences would have been the opposite!
Edwards Park (editor at Smithsonian) always had good things to say about the P-39, especially his aircraft Nanette, who always developed technical problems forcing him to return to base before a really tough mission.
Cheers,
Dana
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Could it be because they preferred P-40s but they might be harder to find in 1944? Was the request for more P-39s because of attrition and no-one else wanted them, thus the P-39 might be available?
Shortround6
Lieutenant General
Very hard to say without further research.
P-38 production ended in Aug 1944 with 1729 planes built that year while P-40 production ended in Nov 1944 with 2002 planes built that year.
However for both planes their production numbers were being split 3/4 ways?
Replacements to existing units equipped with them as some units got newer types of aircraft (P-47s and P-51s).
Lend-lease aircraft for lesser allies.
Planes sent to US training units.
Lend-lease aircraft sent to Russia.
Dividing up these larger categories into sub categories is where the research would come in.
As would actual timing (month) and theater. Planes sitting outside the factory or in USAAC depot in the US is several months away from US units in the Pacific or CBI (or Russia) and also may depend on shipping space. On a local level a P-39 squadron or group may have traded in their aircraft for P-47s/P-51s creating a local surplus of P-39s while replacement P-40s were in short supply for the next month or two.
Difference between 1942 and 1944 is also not to be ignored. Was the Japanese AA better or worse? More guns or fewer? better or worse gunners? less ammo restricted rounds fired per attack? Did late model P-39s get any extra belly armor by 1944?
I have read about several of these things but cannot prove them one way or the other.
No. Quite surprisingly, they considered the P-39 superior for their purposes. Pilot preference was mentioned, but I'd have loved to have seen a more complete explanation...
Cheers,
Dana
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Ditto.
Geoffrey Sinclair
Staff Sergeant
- 1,278
- Sep 30, 2021
Perhaps the 13th Air Force liked the 37mm cannon given the missions they were flying late 1943 and early 1944. When is the 1944 document dated? Deliveries in USA by customers.
Reported strengths, CONUS and Overseas is all USAAF. The 5th+13th Air Force P-39 and P-40 are only available to end August 1945 Second line is no doubt where a lot of P-39 and P-40 ended.
| Model | P-39Q | P-39Q | P-39Q | P-39Q | P-40N | P-40N | P-40N | P-40N | P-40N | P-40N | P-40N |
| For | USA | Britain for | USSR | France | USA | Australia | Brazil | China | Netherlands | New | USSR |
| Month | USA | Russia | USSR | France | USA | Australia | Brazil | China | East Indies | Zealand | USSR |
Jan-44 | 115 | 46 | 248 | 45 | 157 | 10 | 6 | 50 | |||
Feb-44 | 94 | 201 | 63 | 15 | 169 | 20 | 12 | 15 | 20 | 50 | |
Mar-44 | 8 | 196 | 129 | 15 | 197 | 9 | 6 | 20 | |||
Apr-44 | 1 | 115 | 98 | 219 | 1 | 6 | 50 | ||||
May-44 | 2 | 125 | 37 | 127 | 10 | 12 | 34 | ||||
Jun-44 | 132 | 109 | 35 | 9 | 46 | ||||||
Jul-44 | 1 | 103 | 90 | ||||||||
Aug-44 | 24 | 116 | 20 | 14 | |||||||
Sep-44 | 125 | 59 | 6 | 12 | |||||||
Oct-44 | 93 | 81 | 21 | ||||||||
Nov-44 | 43 | 42 | |||||||||
Dec-44 | 2 | ||||||||||
Jan-45 | 1 | ||||||||||
Feb-45 | 2 | ||||||||||
Mar-45 | 2 | ||||||||||
| Total | 221 | 815 | 811 | 75 | 1,378 | 261 | 41 | 36 | 33 | 20 | 250 |
Reported strengths, CONUS and Overseas is all USAAF. The 5th+13th Air Force P-39 and P-40 are only available to end August 1945 Second line is no doubt where a lot of P-39 and P-40 ended.
| Model | P-39 | P-40 | P-39 | P-40 | P-39 | P-40 | 2nd Line |
| For | CONUS | CONUS | Over | Over | Far East | Far East | Far East |
| Month | CONUS | CONUS | Seas | Seas | Air Force | Air Force | Air Force |
Jan-44 | 1,204 | 1,015 | 864 | 1,260 | 93 | 117 | 88 |
Feb-44 | 1,212 | 1,129 | 938 | 1,201 | 98 | 104 | 100 |
Mar-44 | 1,054 | 1,324 | 989 | 1,093 | 95 | 98 | 136 |
Apr-44 | 1,000 | 1,471 | 942 | 1,028 | 109 | 99 | 147 |
May-44 | 949 | 1,508 | 844 | 926 | 103 | 88 | 168 |
Jun-44 | 783 | 1,488 | 618 | 826 | 22 | 80 | 206 |
Jul-44 | 757 | 1,540 | 541 | 746 | 74 | 256 | |
Aug-44 | 671 | 1,428 | 492 | 668 | 135 | 267 | |
Sep-44 | 662 | 1,481 | 353 | 609 | 126 | 242 | |
Oct-44 | 633 | 1,531 | 211 | 459 | 83 | 312 | |
Nov-44 | 620 | 1,417 | 202 | 405 | 69 | 296 | |
Dec-44 | 552 | 1,365 | 194 | 351 | 67 | 175 | |
Jan-45 | 478 | 1,286 | 187 | 278 | 66 | 127 | |
Feb-45 | 440 | 1,257 | 135 | 265 | 67 | 111 | |
Mar-45 | 241 | 1,160 | 113 | 230 | 59 | 99 | |
Apr-45 | 129 | 1,107 | 108 | 174 | 42 | 172 | |
May-45 | 52 | 909 | 104 | 122 | 37 | 143 | |
Jun-45 | 30 | 652 | 67 | 111 | 35 | 138 | |
Jul-45 | 24 | 355 | 29 | 79 | 30 | 133 | |
Aug-45 | 5 | 45 | 17 | 71 | 30 | 111 | |
Sep-45 | 2 | 11 | 16 | 24 | |||
Oct-45 | 2 | 1 | 10 | 34 | |||
Nov-45 | 1 | 1 | 33 | ||||
Dec-45 | 1 | 1 | 20 |
GregP
Major
Hard to explain the continued production of the P-39 except to keep Bell Aircraft as a viable source of airplanes. The P-63 was a good airplane, if short legged, but the P-39 was really not a very good airplane unless most of the ammunition was still in the nose.
pinehilljoe
Staff Sergeant
Just like now, it could be as simple as the New York State Congressional lobby keeping money and jobs going in Buffalo.
GregP
Major
Could be. The last people they ever ask are the pilots who will fly the aircraft ...
This was all the work of Soviet agents. The Soviets needed an excellent aircraft for the Eastern Front, for which they would not need to compete with the USAF. And complaining about certain shortcomings of the aircraft was, to put it mildly, not encouraged in the Soviet Air Force.
PS. I wasn't serious.
I had a long conversation long ago with a pilot that flew the P39 in combat. He rated it the equal of the P40 without the ground loop issues and he said the flat spin never actually happened to his knowledge. Certainly not in his squadron, while he lost two buddies to P40 ground loops.
GregP
Major
We used to have former WWII pilots give a talk at the Museum every month. I have spoken to maybe 85 or them. We don't have that anymore due to no former WWII pilots being available. They tapered off right around 2014 or so, give or take a year or two, about 70 years after the end of the war.
Most of the pilots who flew low missions in the Pacific, as in under 15,000 feet and mostly under 10,000 feet, liked the P-39. Once it got much above 12,000 feet, they didn't like it. Most of them never emptied their ammo very often. When they did, it was tricky to fly and the stick force per g went WAY down, making it hard to execute abrupt turns without stalling since anything but slight pressure on the stick would produce a large pitch movement. That behavior was OK if you were flying home after a short mission, but very tiring if you had any distance to go. Of course, with the available gas, no actual flying distances were very long to start with ...
I wasn't there, but that's the behavior they described. I'd say maybe 20 or so former P-39 pilots.
It climbed very well down low, up to about 12,000 feet or so and turned about as well as a P-40. But it had short legs and warm, if not hot, cockpit.
Again, that is "as describedby the pilots." I have no way to absolutely verify it and make no claim it was the real "way it was." But, personally, I believe them.
Most of the pilots who flew low missions in the Pacific, as in under 15,000 feet and mostly under 10,000 feet, liked the P-39. Once it got much above 12,000 feet, they didn't like it. Most of them never emptied their ammo very often. When they did, it was tricky to fly and the stick force per g went WAY down, making it hard to execute abrupt turns without stalling since anything but slight pressure on the stick would produce a large pitch movement. That behavior was OK if you were flying home after a short mission, but very tiring if you had any distance to go. Of course, with the available gas, no actual flying distances were very long to start with ...
I wasn't there, but that's the behavior they described. I'd say maybe 20 or so former P-39 pilots.
It climbed very well down low, up to about 12,000 feet or so and turned about as well as a P-40. But it had short legs and warm, if not hot, cockpit.
Again, that is "as describedby the pilots." I have no way to absolutely verify it and make no claim it was the real "way it was." But, personally, I believe them.
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Steamed_Banana
Staff Sergeant
- 1,146
- Sep 29, 2025
Early P-39s had a lot of 'teething' issues, particularly the P-400s (I really need to take a deep dive somewhere and find out why they couldn't get any British oxygen tanks or whatever gear they needed to swap out the O2 system to an American one). But the P-39, particularly later models, had some advantages over the P-40, especially once some of those problems were ironed out.
A plane like a P-39Q had a much faster initial climb rate than any P-40 (almost double the ROC in some cases), which could be quite valuable for interception missions. Might be very good to be at fighting altitude in five minutes instead of ten when the IJN or JAAF are coming. It was also a fair bit faster in overall speed than the P-40, both in terms of top speed and speed at various altitudes, as well as acceleration and speed retention. This could be good for both interception and evading enemy fighters. And it was a bit smaller which has some advantages. I don't think it was as agile (in terms of roll rate) or turned quite as well, depending on the exact variants, but the Soviets considered it better than the P-40 for 'vertical maneuvers', probably because of it's climb rate. P-39 was also good for strafing ground targets which is a lot of what USAAF units were doing by 1944, with the heavy gun in the nose plus being a smaller target for AAA. The heavy gun could also be useful when intercepting bombers.
And to Greg's point, landing and takeoff was a bit easier with the nosewheel.
The downsides were range, and handling, which, nose balance issues or not, was clearly trickier in the P-39 than with most other Anglo-American fighters. Also less bomb capacity when compared to later model P-40s.
And it's notable that there was only ever one US P-39 Ace recognized as such by the USAAF and none of our Allies seem to have done much with it. There were 40 or 50 P-40 Aces in the USAAF alone, not counting British, Australian, Kiwi, South African or other Commonwealth or Soviet pilots. P-39 units did seem to shoot down a fair number of Japanese planes in New Guinea and in the Solomons, while even the P-400s were valuable as strafers and fighter-bombers, and it even had some merits in the North African / Mediterranean Theater, but they never really held their own. I don't think any US P-39 units achieved parity with Axis fighters in terms of losses vs claims, let alone actual losses on each side. It was more like 1-2 in terms of claims, at best.
The main value in manufacturing lots of P-39s, and the same goes for the whole run of the P-63, was for Soviet use. It's pretty clear that the USAAF / War Dept thought that it would be the replacement for the P-40 and a good bridge to the later model fighters, but that never happened. They were suddenly all over the place in late 1942 and early 1943, but then faded away as the truth of their disappointing outcomes finally sunk in. Perhaps the saddest thing about the P-39 is the number of lives lost in some of the best pilots among our Allies who converted from the Fascist side from Vichy France and Italy who had them foisted upon them, just in landing accidents and such. It would have been better if they had just been given some of the large stocks of extra Spitfire Vc that were all over, or some P-47s.
A plane like a P-39Q had a much faster initial climb rate than any P-40 (almost double the ROC in some cases), which could be quite valuable for interception missions. Might be very good to be at fighting altitude in five minutes instead of ten when the IJN or JAAF are coming. It was also a fair bit faster in overall speed than the P-40, both in terms of top speed and speed at various altitudes, as well as acceleration and speed retention. This could be good for both interception and evading enemy fighters. And it was a bit smaller which has some advantages. I don't think it was as agile (in terms of roll rate) or turned quite as well, depending on the exact variants, but the Soviets considered it better than the P-40 for 'vertical maneuvers', probably because of it's climb rate. P-39 was also good for strafing ground targets which is a lot of what USAAF units were doing by 1944, with the heavy gun in the nose plus being a smaller target for AAA. The heavy gun could also be useful when intercepting bombers.
And to Greg's point, landing and takeoff was a bit easier with the nosewheel.
The downsides were range, and handling, which, nose balance issues or not, was clearly trickier in the P-39 than with most other Anglo-American fighters. Also less bomb capacity when compared to later model P-40s.
And it's notable that there was only ever one US P-39 Ace recognized as such by the USAAF and none of our Allies seem to have done much with it. There were 40 or 50 P-40 Aces in the USAAF alone, not counting British, Australian, Kiwi, South African or other Commonwealth or Soviet pilots. P-39 units did seem to shoot down a fair number of Japanese planes in New Guinea and in the Solomons, while even the P-400s were valuable as strafers and fighter-bombers, and it even had some merits in the North African / Mediterranean Theater, but they never really held their own. I don't think any US P-39 units achieved parity with Axis fighters in terms of losses vs claims, let alone actual losses on each side. It was more like 1-2 in terms of claims, at best.
The main value in manufacturing lots of P-39s, and the same goes for the whole run of the P-63, was for Soviet use. It's pretty clear that the USAAF / War Dept thought that it would be the replacement for the P-40 and a good bridge to the later model fighters, but that never happened. They were suddenly all over the place in late 1942 and early 1943, but then faded away as the truth of their disappointing outcomes finally sunk in. Perhaps the saddest thing about the P-39 is the number of lives lost in some of the best pilots among our Allies who converted from the Fascist side from Vichy France and Italy who had them foisted upon them, just in landing accidents and such. It would have been better if they had just been given some of the large stocks of extra Spitfire Vc that were all over, or some P-47s.
SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
Remove the nose armor.
Steamed_Banana
Staff Sergeant
- 1,146
- Sep 29, 2025
I double checked, 30 US Aces on P-40 in the Pacific, 38 in the CBI (counting AVG), 18 in the Med, looks like 86 total US.
There was another 46 Commonwealth and British (counting only those who made 5 or more victories on type).
Not sure how many Soviet but just eyeballing a list of Soviet aces it looks like at least 20 or 30.
One US ace on the P-39, William Fiedler JR with the 347 FG over Guadalcanal.
165 aces flying the P-38 (I saw another claim saying it was 100)
74 aces flying Wildcats (26 USN, 48 USMC)
305 US aces flying F6F Hellcat
looks like 47 US aces flying F4U during WW2 (23 USMC and 24 USN)
I couldn't find a count of the P-51 Aces but there is a list of them here
also couldn't find a total count or a list of P-47 aces, surprisingly.
There were either 4 or 5 P-61 night-fighter aces
There was another 46 Commonwealth and British (counting only those who made 5 or more victories on type).
Not sure how many Soviet but just eyeballing a list of Soviet aces it looks like at least 20 or 30.
One US ace on the P-39, William Fiedler JR with the 347 FG over Guadalcanal.
165 aces flying the P-38 (I saw another claim saying it was 100)
74 aces flying Wildcats (26 USN, 48 USMC)
305 US aces flying F6F Hellcat
looks like 47 US aces flying F4U during WW2 (23 USMC and 24 USN)
I couldn't find a count of the P-51 Aces but there is a list of them here
also couldn't find a total count or a list of P-47 aces, surprisingly.
There were either 4 or 5 P-61 night-fighter aces
drgondog
Major
Fiedler was killed when a landing P-38 collided with his P-39 on the runway. Guadalcanal.
.
Steamed_Banana
Staff Sergeant
- 1,146
- Sep 29, 2025
Damn... harsh!
